Supposing there's no air
resistance, horizontal velocity is constant, which makes it very easy to solve
for the amount of time that the rock was in the air.
Initial horizontal
velocity is: <span>
cos(30 degrees) * 12m/s = 10.3923m/s
15.5m / 10.3923m/s = 1.49s
So the rock was in the air for 1.49 seconds. </span>
<span>
Now that we know that, we can use the following kinematics
equation:
d = v i * t + 1/2 * a * t^2
Where d is the difference in y position, t is the time that
the rock was in the air, and a is the vertical acceleration: -9.80m/s^2. </span>
<span>
Initial vertical velocity is sin(30 degrees) * 12m/s = 6 m/s
So:
d = 6 * 1.49 + (1/2) * (-9.80) * (1.49)^2
d = 8.94 + -10.89</span>
d = -1.95<span>
<span>This means that the initial y position is 1.95 m higher than
where the rock lands. </span></span>
Complete Question
Suppose you have three identical metal spheres, A, B, and C. Initially sphere A carries a charge q and the others are uncharged. Sphere A is brought in contact with sphere B, and then the two are separated. Spheres CC and BB are then brought in contact and separated. Finally spheres AA and CC are brought in contact and then separated. What is the final charge on the sphere B, in terms of q?
a. 3/8q
b. 1/4q
c. 3/4q
d. q
e. 5/8q
f. 1/3q
g.1/2q
h. 0
Answer:
The correct option is b
Explanation:
From the question we are told that
The charge carried by A is q C
The charge carried by B is 0 C
The charge carried by C is 0 C
When A and B are brought close and then separated the charge carried by A and B is mathematically evaluated as

When C and B are brought close and then separated the charge carried by C and B is mathematically evaluated as

When C and A are brought close and then separated the charge carried by C and A is mathematically evaluated as

Looking at these calculation we can see that the charge carried by B is

If it takes 42 minutes to load 3 1/2 trucks, then it takes 42 / 3.5 = 12 minutes to load a single truck. Multiplying the number of minutes per truck by 6.5 yields the time it will take to load. In this case 12 x 6.5 = 78 minutes would be required to load 6 1/2 trucks. The formula for the time taken is t = 12n, where t is the time in minutes and n is the number of trucks.
FALSE <span>Only electromagnetic </span>waves<span> can </span>travel through a vacuum<span>; mechanical </span>waves<span> such as sound </span>waves<span> require a particle-interaction to transport their energy. There are no particles in a </span>vacuum<span>. </span>Waves<span> are either </span>longitudinal<span> or transverse.
</span>Hoped i helped :):)